Design method for changing casting guide vane to welded guide vane, welded guide vane and guide vane body

Abstract

The invention provides a design method for changing a cast guide vane into a welded guide vane. The design method of changing the cast guide vane to welded guide vane includes the following steps: calculate the average cross-sectional area of ​​the casting guide vane along the flow channel, and design the cross-sectional area of ​​the welded guide vane to be equal to the According to the average cross-sectional area of ​​the water, the axial projection of the welding guide vane is determined according to the axial projection of the casting guide vane; the design of the welding guide vane includes a first plane area, a second plane area and a The cylindrical area between the first plane area and the second plane area, under the premise that the inlet angle, outlet angle and wrap angle of the welded guide vane are respectively equal to the inlet angle, outlet angle and wrap angle of the cast guide vane , adjusting the blade shape of the welded guide vane according to the blade shape of the cast guide vane. The present invention also provides a welded guide vane designed by the above design method and a guide vane body using the above welded guide vane.

Description

technical field [0001] The invention relates to the field of design and manufacture of water pump guide vanes, in particular to a design method for changing a cast guide vane to a welded guide vane, a welded guide vane designed by the design method and a guide vane body using the welded guide vane. Background technique [0002] The guide vane is the energy transfer device of the water pump. Its function is to collect the liquid thrown out by the impeller, reduce the flow rate of the liquid, and convert part of the velocity energy head into the pressure energy head, and then introduce it into the next stage evenly or through diffusion. tube discharge. [0003] In order to meet the requirements of rigidity and strength, the traditional casting guide vane leaves more margin to make the blades of the guide vane relatively thicker, so it will cause a certain blocking effect in the flow channel. Moreover, the traditional casting guide vane also has the following disadvantages: du...

AI Technical Summary

Problems solved by technology

[0003] In order to meet the requirements of rigidity and strength, the traditional casting guide vane leaves more margin to make the blade of the guide vane relatively thicker, so it will cause a certain blocking effect in the flow channel

Moreover, the traditional casting guide vane also has the following disadvantages: due to the restriction of casting precision, the surface of the internal flow channel of the casting guide vane is not smooth enough, which will cause a certain hydraulic loss; the weight of the casting guide vane is relatively heavy, and more materials are required This leads to higher costs; defects such as pores, shrinkage cavities, sand holes and cracks are prone to occur during the casting process, and repairing unqualified castings will increase a lot of labor costs and material costs; dust, harmful gases and noise generated during the casting process have a negative impact on Environmental pollution is more serious than other mechanical manufacturing processes

[0005] At present, many manufacturers at home and abroad are beginning to try to change the cast guide vanes into welded guide vanes, but there are still some urgent problems to be solved in the transformation: the welded guide vanes of many manufacturers have been transformed to make the curved surface tend to be straight for the convenience of processing. Reducing the overall size, which is very different from the shape of the original casting guide vane, is equivalent to designing a completely different new guide vane model. This guide vane will cause the kinetic energy of the liquid flowing out of the impeller to be unable to be completely converted into pressure energy to a certain extent. , cannot eliminate the liquid rotation component, resulting in more energy loss and lower efficiency

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